You’ll discover the message in OS X 10.8 when you try to launch DSS Player for Mac install and you’ll get an alert dialog that says “DSSPlayerV7.mpkg" can’t be opened because it is from an unidentified developer”.

This error typically occurs when you try to launch a program that didn't come from a verified source or from the Mac App Store.

Resolution

Disable GateKeeper’s Unidentified App Developer Prevention. You can find Gatekeeper settings in System Preferences > Security & Privacy > General.

• To disable Gatekeeper, click on the lock on the lower left of the window and type in your system password.
• Under option “Allow applications downloaded from:” choose “Anywhere".
• Accept the security warning and allow.

You can now launch any app from any location or developer.